when your carton of milk is empty. you scan the barcode using a reader on the fridge and the fridge then makes an order to get more milk delivered, using the bitcoins you deposited into the bitcoin address for the fridge.  you fridge is then in full control of selecting the goods on the foodstores website, and paying them.
that way you dont have to even order food/drink . you just scan barcodes and wait for the delivery driver to turn up.